Add a documented and semi-automated release process

[kurtmckee]

Development

• Add a documented and semi-automated release process.

[derek-globus]

I like the usage of just as an entry point for different steps.

I wonder if it'd mesh better with other just recipes to nest as subcommands like 'just release r1', 'just release r2', etc. (not married to that exact phrasing if you liked the details of each step included in the recipe name, moreso suggesting that we keep recipes at the same level of abstraction)

Overall though, this is nice & simplifies the releasing process well

[kurtmckee]

I found the tab completion of e.g. just r1<tab> very favorable; I think that nesting under a just subcommand (like just releasing r1) is doable but it's not the direction I took this time around.

I also don't know how the subcommand idea might appear in the just -l rendering, but maybe just has renders something like that in a smart way. The current rendering is pleasant:

$ just -l
Available recipes:
    clean                   # Delete known build artifacts.
    docs                    # Rebuild the project's documentation locally (at ./`build`).
    help                    # Print this help message.
    install                 # Install a development virtual environment (at `./.venv`) and pre-commit hooks.
    lint                    # Run pre-commit checks on all files.
    mypy filepath="./src"   # Type check the project with mypy.
    r1-prep-release version # RELEASING 1: Create a new branch and update the project metadata.
    r2-amend-changelog      # RELEASING 2: (OPTIONAL) Amend the CHANGELOG after changes are made.
    r3-create-pr            # RELEASING 3: Create the release PR.
    r4-publish              # RELEASING 4: Publish a git tag and GitHub release.
    r5-merge-back           # RELEASING 5: Create the merge-back-to-main PR.
    test                    # Run the full test suite locally.